Webpack Boilerplate for Cloudflare Workers

A superbly simple, minimal-config launchpad to build, bundle and deploy Cloudflare Workers with Webpack 🚀

NOTE: You should probably just use Cloudflare's official tool, Wrangler, at this point.

Why this is

Webpack is the recommended means for Cloudflare Worker developers to leverage npm's massive, modular ecosystem. But to those unfamiliar with Webpack's black magic configuration, it can mean investing countless hours in tooling-tweaks and .*rc-file-fiddling.

So the goal, here, is to provide a fiddle-free, Webpack-powered launchpad with default settings sane enough for almost any use case.

It'll bundle up your script and dependencies, upload your Worker to Cloudflare, and even activate its route(s). The world's now yours to require('🌍')

What you configure

• Your Cloudflare credentials
• Your site name (FQDN) or Cloudflare Zone-Id
• (Optional) One or more route matching patterns for your Worker

What you get

• Transparent, optimized and ready-to-rock Webpack configuration file
• Babel configuration ensuring development-setup build compatibility for Node 8+ and script compatibility with the latest V8 runtime
• On-demand polyfilling in the (very unlikely) event that it's needed
• Baked-in management of route patterns
• Minification of Worker scripts to keep them under the 1MB limit
• A deployable example to demonstrate require and other neat features
• Access to secret keys, tokens, and certificates using CF-Worker secrets vault
• Namespace resource bindings for the funky-fresh new Workers KV 👏

Requirements

• Node 12 or later
• Cloudflare account with domain

Quick Start

1. Clone this repository:

   git clone git@github.com:detroitenglish/cloudflare-workers-webpack-boilerplate.git
   
   cd cloudflare-workers-webpack-boilerplate

2. Rename example.env to .env , and add your required Cloudflare credentials, and either your site name or site's zone-id.

3. Install dependencies with npm install

4. Write your worker script in src/worker.js

   • Install any dependencies for your worker with: npm install -P <some-npm-module>
   • Build a preview of your bundled worker script in dist/bundled-worker.js by running: npm run build

5. Build, bundle and launch your minion Worker to the Cloudflare Edge 🚀 using: npm run deploy

Example Cloudflare Worker

A ready-to-rock example Worker script can be found in src/example.worker.js.

The example Worker require()s lodash.sample, and uses it to randomly choose a translation of the word 'hello'.

It then adds a response header in the form of:

x-worker-greeting: <random-hello>, world!

Using the Example Worker

After completing steps 1-3 above, you can build the example script with npm run build:example

You can deploy it live to your site with npm run deploy:example

To get the full experience, create a KV Namespace and add its namespace_id to src/example.metadata.json

Configuration

Required Config

Cloudflare Credentials

The following are required in your .env file:

• CLOUDFLARE_AUTH_EMAIL: Your Cloudflare account email address

• CLOUDFLARE_AUTH_KEY: Your Cloudflare API-Key

Site Identification

You must provide a means of identifying your Cloudflare site deployment target by defining (in .env) either:

• CLOUDFLARE_ZONE_ID: The Zone ID to which your worker will be deployed

or

• CLOUDFLARE_SITE_NAME: The fully qualified domain name (FQDN) of your site, e.g. example.lol

Additional Config

More options are defined and described in example.env

Default Settings & Behaviors (Advanced)

Minification

Webpack is configured to minify scripts before deployment in order to help keep your bundled Worker under the 1MB limit.

Building previews with npm run build will not minify scripts in order to make debugging easier.

CloudflareWorkerPlugin

Worker script uploading and route pattern management are handled by the this same author's cloudflare-worker-webpack-plugin. You can review the plugin's source code and documentation here.

Babel Configuration

Babel is configured to let you use JavaScript syntaxes and features that are supported in the latest version of Chrome, but not natively supported by NodeJS, e.g. import "statements" or { ...objectSpreadSyntax }.

On build, Babel will only add polyfills to your bundled script if, after evaluating your code, it determines a polyfill is necessary for compatibility with the latest version of Chrome (a very unlikely scenario).

Custom .env Variables

See example.env for details and examples on adding and injecting custom variables.

Cloudflare Worker Secrets Vault

See example.env for details and examples on including a metadata.json secrets file.

Route Patterns

See example.env for details and examples on how route patterns are parsed and deployed.

Relevant Resources

• Cloudflare Workers documentation

• Clouflare-Worker-Webpack-Plugin documentation

• Webpack Config documentation

• Babel's preset-env documentation

• dotenv documentation

Development

Testing and Issue Reporting

I am not a Cloudflare employee, so as a peasant my testing is limited to my own Workers, in my own zones for my own application in production.

So by all means, try to break stuff! And if something goes kaputt, please let me know by creating an issue.

Contributing

PRs are very much welcome 👍

Committing will trigger - and must pass - linting and a few tests (...which there could be more of!)

Fork away!

Roadmap

Some ideas going forward:

• Replace zone-id requirement with automatic zone-lookup of FQDN
• Setup CI for deployment tests with the Cloudflare API
• Support single-shot deployment to multiple zones Meh...
• Add argument parsing (or actual binary?) for deployment via pure CLI

But I'm very open to suggestions - please share your ideas by creating an issue.

Software Stuff

Disclaimer

Other than a happy customer, I am not affiliated with Cloudflare in any way.

Assume in good faith that I have no idea what I'm doing; REVIEW THE SOURCE, and use at your own risk 🙈

License

MIT